Indicator for steam, gas, and other engines.



J. N. WALLACE. INDICATOR FOB, STEAM, GAS, AND OTHER ENGINES. APPLICATION FILED NOV. 26, 1910,

' 1,080,216. Patented June 18,1912.

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J. N. WALLACE. INDICATOR FOR STEAM, GAS, AND OTHER ENGINES. APPLICATION FILED NOV. 26, 1910' 1,080,21 6. Patented June 18,1912.

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COLUMBIA PLANOGRAPH co. WASHINGTON, D. c.

JAMES NEILSON WALLACE, OF WEST DIDSBURY, MANCHESTER, ENGLAND.

INDICATOR FOR STEAM, GAS, AND OTHER ENGINES.

Application filed November 26, 1910.

Specification of Letters Patent.

Patented June 18, 1912. Serial No. 594,288.

To all whom ti may concern:

Be it known that I, JAMES NEIL-SON Ab LACE, a subject of the King of Great Britain, residing at 66 Northen Grove, West Didsbury, Manchester, in the county of Lancaster, England, have invented certain new and useful Improvements in Indicators for Steam, Gas, and other Engines, of which the following is a specification.

This invention relates to improvements in the class of indicators for steam, gas, and other engines in which a strip of paper is made to move continuously in one direction with a speed proportionate to that of the engine piston and on which strip dilferent pressure diagrams may be simultaneously recorded together with a record of time.

The object of this invention is to obtain continuous indicator diagrams from both ends of a cylinder simultaneously, and on the same strip or roll of paper that may be put in motion or stopped without disconnecting the attachment to the indicating gear, the diagrams being of such a form that the actual effective pressure on the engine piston at any instant may be scaled directly from the diagrams.

A further object is to provide a means for continuously recording the speed of the engine piston on the same strip of paper as the diagrams, in such a manner that the actual total power being developed in the engine cylinder at any instant may be calculated; the arrangement of the improved indicator being such as permits of ordinary indicator diagrams being taken from each end of the cylinder alternately in the ordinary manner when desired.

In the accompanying drawings illustrating my invention and to which I hereinafter refer, Figure 1 is a front elevation and Fig. 2 a plan of my improved indicator; Fig. 3 is a vertical section on line A A of Fig. 2, Fig. 4- is a sectional plan on line B B of Fig. 3, Fig. 5 is a sectional plan on line C C of Fig. 3, Fig. 6 is a plan of the upper part of the barrel G as shown in Fig. 3. In these views the same letters refer to like parts.

According to and for the purpose of my invention, I employ a piping P, one end of which is connected to one end of an engine cylinder X and the other end of the piping to the other end of the cylinder X in the ordinary manner. Two indicator control taps V are fitted in this piping at such a distance apart that the tracing pencils (4 and a of the two indicators a and a fitted on said taps may be free to move in closely adjacent planes on'the surface of an auxiliary or paper carrying drum 7' common to the two indicators, and adjustably mounted centrally between the two indicators (4 and a on a bracket Z) secured to the arms a and a of said indicators. In order that each indicator may be put in communication with either end of the cylinder as required, three taps V, V and V are fitted on the aforesaid piping; one of these taps V is placed between the indicator taps V, for instance one tap, V is placed between one of the indicator taps and one end of the cylinder, and the other tap V is placed between the other indicator tap and the other end of the cylinder. To obtain continuous diagrams a roll of paper f is placed in the auxiliary drum 7 and the end brought through an opening 7 in the side of said drum; the end of the paper is carried around the ten sion rollers f around the drum 7 under the tension roller f and received on the paper receiving drum or barrel 0 of the indicator a, the paper passing under the pencils a and a of the two indicators with a motion at a. right angle to that of the pencils continuously in one direction, and with a speed at all times proportionate to that of the engine piston. To effect this I fit on to a spindle (6 Fig. 3, which is nonrotatably fixed on the arm a of the indi cator a, two concentric sleeves, each carrying a cord drum 0 and c". A cord 0, Fig. 5, which may be connected to the indicating gear of the engine, is wound upon the cord drums c and 0 one end 0 of said cord is secured to and passed around the drum 0 in one direction, and the other end 0 of the cord is secured to and passed around the drum 0 in the opposite direction.

0 is a spring common to the two drums, that is to say, one of its ends is secured to the drum 0 and the other end to the drum 0 so that when the cord is moved by the indicating gear of the engine, said cord drums and c are moved simultaneously in reverse directions with a peripheral speed proportionate to that of the engine piston. Stops are provided to maintain the requisite initial tension on the spring 0 and to limit the rotational travel of the drums.

The cord drums c and c carry clutches (Z and (Z respectively, (see Figs. 3 and l),

which alternately engage with a rotatable sleeve piece (Z arranged to slide within the barrel 0, on which is received the aforesaid fixed spindle a and which clutches impart to the said sleeve piece (Z a rotary motion continuously in one direction, andaperipheral speed proportionate tothat of the engine piston. In the forward movement of the engine indicating gear one of the cord drums, say 0 would be positively rotated while the other, 0 would be negatively rotated and the corresponding clutches (Z2 and (Z would be in and out of gear respectively with the sleeve piece (Z which would consequently be positively rotated by the clutches (Z while the clutches (Z run back free. In the backward movement of the engine indicating gear the spring 0* would positively rotate the cord drum 0 and negatively rotates the cord drum 0 and this would resultin the positive rotation of the clutches (Z and the backward negative and ineffective rotation of the clutches (Z and the sleeve piece (Z would again be driven forward positively, but this time by the clutches 6 on the cord drum 0 instead of by the clutches d2 on the other cord drum. Hence whether the engine indicating gear is running forward or backward the sleeve piece (Z will always be advanced bythe clutches on one or other of the cord drums.

The barrel 0 has a spring clutch e which may be caused to engage in a recess 6 in the flange e of the sleeve piece (Z and to revolve with it. When it is required to stop the rotation of the barrel 0 and with it the paper strip f ,the plate 6 which is eccentrically pivoted on the spindle a is moved around and engages with a projection on the spring clutch 6*, and withdraws the clutch from the recess 6 thereby disengaging the barrel 0 from the rotatable sleeve piece (Z, and by a further movement of the plate 6 the clutch e is locked between the plate 6 and the spring 6 secured to the top of the barrel 0, thereby preventing any motion of the barrel 0.

WVhen continuous diagrams require to be taken the barrel clutch 6* is made to engage with the aforesaid rotatable sleeve piece (Z and to revolve with it and so withdraw the paper strip f from the auxiliary drum f with a motion and speed as aforesaid. At the same time the indicator (4 is put in communication with one end of the engine cylinder, and the indicator (4 put in communication with the other end of said cylinder, and the tap between the two indicator taps closed. The indicator pencils a and a then trace two lines on the paper strip f which at any instant represent the forward and back pressures on the engine piston, and the difference between the two pressures is the efiective pressure on the piston.

As the indicator pencils a and a are very close together on the paper strip f, it is obvious that the continuous line of diagrams traced by the second pencil, the pencil 64 will be superimposed upon the continuous line of diagrams already traced on the paper strip by the pencil a and that as the pencils are connected to the opposite ends of the same cylinder, the closed figures produced by the superimposition of the two continuous diagrams will at all times represent the true maximum and minimum pressure on the piston.

Each reversal of the motion of the piston in the engine cylinder is recorded automatically on the continuous paper strip f, and in. the same plane in which the indicator pencils record the pressure diagrams simultaneously by means of a lever h pivoted on a lever 7% that is pivoted on the end I) of the bracket Z2; one end of the lever h carries a friction roller or an equivalent 72?, which engages in a groove 0 either in the cord drum 0 as shown or in the cord drum 0, and has imparted to it a slight rocking motion limited by the stops h at each reversal of the direction of rotation of said cord drum; the opposite end of the lever h is connected to one end of a bellcrank lever h by a rod 7L5, the other end of the bellcrank carrying the pencil it which records the reversals on the paper f.

In order to render the recording pencil h inoperative when not required, I fit a lever h" controlled by a spring 7L on the bracket Z), by which the frictional contact between the cord drum and the lever k may be interrupted when necessary.

Time is recorded on the paper and in the same plane as that in which the indicator pencils move at intervals which may be varied, by clockwork, in the manner such as ordinarily employed, and this is efiected by a series of wheels having varying numbers of ratchet shaped teeth, any one of which wheels such as 2' may be attached to the arbor of the escapement wheel 2' and communicate a slight rocking motion to a pivoted lever i carrying a tracing pencil 2". By these means, given the radius of the engine crank and the length of the engine connecting rod, the piston speed at any instantmay be determined from the record of piston reversals and the record of time.

The paper barrel a of the indicator a is not required when continuous diagrams are being taken, and it may be used for taking ordinary diagrams in the ordinary manner by moving the pencil arm a into the position indicated by the dotted lines and arrow in Fig. 2.

I-Iaving fully described my invention, what I claim and desire to secure by Letters Patent is 1. Means for obtaining continuous and superimposed indicator diagrams, comprising in combination, an indicator (a) a paper receiving drum (0) adapted to be continuously rotated in one direction, means for operatively connecting the said drum to a reciprocating part moving into the engine piston to actuate said drum with a speed at all times proportionate to that of the engine piston, a second engine indicator ((4'), a paper carrying drum (f), a strip of paper carried by said paper carrying drum and operatively connected to said paper receiving drum so as to be positively wound upon the latter and arranged so that the tracing pencils of the two indicators move in closely adjacent planes on the paper and substantially parallel to the axis of the carrying drum, and means for connecting the said indicators to the opposite ends of the main engine cylinder.

2. Means for obtaining continuous and superimposed indicator diagrams, comprising in combination, an indicator (a) a paper receiving drum adapted to be continuously rotated in one direction, means for operatively connecting the said drum to a reciprocating part moving in unison with the engine piston to actuate the drum with a speed at all times proportionate to that of the engine piston, a second or paper carrying paper drum (a a third or paper carrying drum (f), a strip of paper carried by said third mentioned and first mentioned drums to be positively wound upon the latter and arranged so that the tracing pencils of the two indicators moving closely adjacent planes on the paper substantially parallel to the axis of the third mentioned drum, a second engine indicator (a), adapted to be rotated in a reciprocating manner and its pencil capable of being moved to an operative position with respect to said second mentioned drum, or to be swung to cooperate with said first mentioned engine indicator whereby the tracing pencil thereof moves in a closely adjacent plane with respect to the pencil of the first mentioned indicator and in parallel relation to the axis of the third mentioned drum, and means for connecting the two indicators to the opposite ends of the main engine cylinder.

3. In apparatus of the character described, the combination of a paper receiving drum; means for continuously rotating the paper receiving drum in one direction, comprising two cord drums concentrically mounted on the drum spindle, a cord connected to a reciprocating part of the engine and oppositely wound around said cord drums, a spring connected to both cord drums so as to reversely rotate them simultaneously, clutches on said cord drums, and a concentric rotatable sleeve mounted 011 the drum spindle and adapted to be engaged alternately by the clutches carried by the two cord drums to cause said sleeve to rotate continuously in one. direction; and a clutch on the paper receiving drum whereby it may be positively connected with the rotatable sleeve and the said paper receiving drum positively locked against movement when disengaged.

4. In apparatus of the character described, means for recording each reversal of the motion of the engine piston automatically on the same continuous strip of paper and in the same plane simultaneously with the pressure diagrams, comprising in combination an engine indicator paper receiving drum, a cord drum thereon, a pivoted lever maintained in frictional contact with said cord drum, and a second lever carrying a tracing pencil and operatively connected with the first lever as to give a vertical movement to the pencil at every reversal of the engine, substantially as described.

5. In apparatus of the character de scribed, means for automatically recording various intervals of time on the same continuous paper strip and in the same plane simultaneously with the pressure diagrams, comprising in combination a clock train carrying a ratchet wheel, a lever pivoted to the indicator with one arm in the path of the ratchet wheel so as to be actuated thereby, and an indicating pencil on the other arm of the lever, substantially as described.

In testimony whereof I have hereunto set my hand in presence of two subscribing witnesses this 18th day of November 1910.

J AMES NEILSON ALLAGE.

IVitnesses:

ERNOLD SIMrsoN MosELEY, MALCOLM SMETHURS'I.

Copies of this patent may be obtained for of Patents,

Washington, D. G. 

